This recipe comes from Bob's Red Mill. They specialize in Gluten Free products. There are many gluten free flours on the market but after doing some research Bob's Red Mill has the best combination of ingredients. Their flour is made from Garbanzo Bean Flour, Potato Starch, Tapioca Flour, White Sorghum Flour, Fava Bean Flour. Gluten free baked goods tend to be dryer and more crumbly in texture that is why the xanthan gum is added to give the baked goods more structure.